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• How can I take a user input in python3 and use it for the file name of ffmpeg-python file output ?

  25 novembre 2022, par tylerdurden4285

  I am trying to do something like this :

  


  import ffmpeg

user_input =input("give your output file a name: ")

(
    ffmpeg
    .input('input.mp4')
    .vflip()
    .output('(user_input).mp4')
    .run()
)



  


  I am wondering how I can take the string input from the user and make it the filename. So if they input "tester" the resulting output file would be "tester.mp4".

  


  I am running it on an ubuntu 20.04 WSL. I'm new to here and doing my best to learn python3 and ffmpeg so please be gentle with me if I broke any community rules. I'll improve as I go.

  


  I don't know what to search for to find the answer to this problem.

  


• ffmpeg : pad filter with transparent background for GIF input/output ?

  23 janvier 2023, par Yami Odymel

  I'm trying to pad the GIF source to a square thumbnail and the extended area should be transparent.

  


  (image source : https://store.steampowered.com/app/2113680/The_Dot/)

  


  

  


  To achieve the goal, I used the following command :

  


  ffmpeg -i ./test/source.gif -filter_complex "[0]scale=255:144[s1];[s1]pad=256:256:0:-56:blue[s2];[s2]split[s3][s4];[s3]palettegen=reserve_transparent=on:transparency_color=blue[p];[s4][p]paletteuse[s5]" -map [s5] -loop 0  ./test/output.gif -y


  


  


  1. [0]scale=255:144[s1]
     First I scale down the image.

     


  


  2. [s1]pad=256:256:0:-56:blue[s2]
     Then pad the image with an uncommon background color : blue

     


  


  3. [s2]split[s3][s4]
     And I split to two streams. One for palettegen and another for paletteuse.

     


  


  4. [s3]palettegen=reserve_transparent=on:transparency_color=blue[p]
     Generate the color palette that indicates blue as the transparency_color

     


  


  5. [s4][p]paletteuse[s5]
     Use the new color palette for output. The padded image with blue background color should be treated as a transparent background.

     


  


  


  But the output animated GIF still has a visible blue background color no matter if I put the paletteuse at first or in the end.

  


  

  


  Related posts :

  


  

  • Making GIFs with ffmpeg : what does "transparency_color" do ?

  


  • How do I resize an animated GIF and keep transparency ?

  


  • Transparency is gone while resizing (scaling) gif using ffmpeg

  


  


• how do I decode an input video using FFmpeg and calculate the PSNR between input and output ?

  27 janvier 2023, par david

  I have an input video in mkv format and want to decode it and calculate the PSNR after decoding. for this aim, I used the following code :

  


  ffmpeg -i input.mkv -f rawvideo -pix_fmt yuv420p output.yuv


  


  but the output is in yuv format and I can not calculate PSNR between it and mkv input file. I am new to using ffmpeg and encoding and decoding. how do I decode the input file and calculate the PSNR value ? is it possible for the output to be in mkv format ? because I use the following code for PSNR calculation but both files have to have the same format.

  


  ffmpeg -i [Input1] -i [Input2] -lavfi psnr -f null -